The Furukawa Electric Co., Ltd.

Fuji Electric Co., Ltd.

Furukawa Automotive Systems Inc.

Shusuke Kaya

Nariaki Ikeda

Sadahiro Kato

Takehiko Nomura

Masayuki Iwami

Yoshihiro Sato

Seikoh Yoshida

Hiroshi Kambayashi

Jiang Li

Ryosuke Tamura

Masatoshi Ikeda, Legal Representative

Katsunori Ueno

Keishi Takaki

Hirotatsu Ishii

Takuya Kokawa

Yuki Niiyama

Takezo Sugimura

Kazuyuki Umeno

Kaoru Sugimoto

Takao Ninomiya

Michio Okubo

Koh Li

Shinya Otomo

Seiji Uchiyama

A power conversion device converting and outputting a characteristic of input power, includes: a power conversion unit including a normally-on type first switching element made of a nitride-based semiconductor material and converting the characteristic of power by a switching operation performed by the first switching element; an operation control unit controlling a switching operation of the first switching element; and an intelligent power switch including: a second switching element provided on a power input side of the power conversion unit and turning on/off power input to the power conversion unit; and a protection control unit including a current detection unit detecting a current flowing in the second switching element and controlling on/off of the second switching element and turn off the second switching element in a case where a current detected by the current detection unit exceeds a threshold value.

Power conversion device with protection device and method of controlling the same

A nitride semiconductor device includes; a semiconductor stack configured with a plurality of semiconductor layers made of nitride semiconductors provided on a base having a conductive portion; a first electrode provided on a portion of a semiconductor layer of the semiconductor layers configuring the semiconductor stack; a second electrode provided on a portion of a semiconductor layer of the semiconductor layers configuring the semiconductor stack separately from the first electrode; a first wiring provided at an upper layer of the first electrode; and a second wiring provided at an upper layer of the second electrode. A low permittivity area being a portion of which permittivity is lower than permittivities of the nitride semiconductors configuring the semiconductor stack at a lower layer of a portion of at least one of the first electrode and the second electrode other than a portion being junctioned with the semiconductor stack electrically.

Nitride semiconductor device, production method thereof, diode, and field effect transistor

The present invention prevents breakage of a gate insulating film of a MOS device and provides a nitride semiconductor device having improved reliability. An SBD metal electrode provided between a drain electrode and a gate electrode is configured to form a Schottky junction with an AlGaN layer. Further, the SBD metal electrode and a source electrode are connected and electrically short-circuited. Consequently, when an off signal is inputted to the gate electrode, a MOSFET part is turned off and the drain-side voltage of the MOSFET part becomes close to the drain electrode voltage. When the drain electrode voltage increases, the SBD metal electrode voltage becomes lower than the drain-side voltage of the MOSFET part, thus the drain side of the MOSFET part and the drain electrode are electrically disconnected by the SBD metal electrode.

Nitride semiconductor device

In a GaN-based semiconductor device, an active layer of a GaN-based semiconductor is formed on a silicon substrate. A trench is formed in the active layer and extends from a top surface of the active layer to a depth reaching the silicon substrate. A first electrode is formed on an internal wall surface of the trench and extends from the top surface of the active layer to the silicon substrate. A second electrode is formed on the active layer to define a current path between the first electrode and the second electrode via the active layer in an on-state of the device. A bottom electrode is formed on a bottom surface of the silicon substrate and defines a bonding pad for the first electrode. The first electrode is formed of metal in direct ohmic contact with both the silicon substrate and the active layer.

GaN-based semiconductor device and method of manufacturing the same

The invention provides a transistor having a leak current between a source and drain in a nitride compound semiconductor formed on a substrate that is reduced. A gate electrode, a source electrode and a drain electrode are formed respectively on the surface of the nitride compound semiconductor formed on the silicon substrate in the transistor. At least one of the source electrode and the drain electrode is surrounded by an auxiliary electrode connected with the gate electrode. Because a depletion layer is formed in the nitride compound semiconductor under the auxiliary electrode, a route of the leak current is shut off and the leak current between the source and drain may be effectively reduced.

Transistor and method for fabricating the same

There is provided a semiconductor device and a method for fabricating the same whose withstanding characteristic may be enhanced and whose ON resistance may be reduced. A MIS-type HEMT includes a carrier traveling layer made of a group-III nitride semiconductor and formed on a supporting substrate, a carrier supplying layer made of a group-III nitride semiconductor and formed on the carrier traveling layer, source and drain electrodes formed on the carrier supplying layer, insulating films formed on the carrier supplying layer and a gate electrode formed on the insulating films. The insulating film is formed in a region interposed between the source and drain electrodes and has a trench whose cross-section is inverted trapezoidal and whose upper opening is wider than a bottom thereof. The gate electrode is formed at least from the bottom of the trench onto the insulating films on the side of the drain electrode.

Semiconductor device and method for fabricating the same

A method of manufacturing a GaN-based field effect transistor is provided by which a lower resistance and a higher breakdown voltage are obtained and which is less affected by a current collapse. A method of manufacturing the GaN-based field effect transistor(s) can comprise performing an epitaxial growth of an AlN layer (), of a buffer layer (), of a channel layer (), of a drift layer () and of an electron supplying layer () in such the order on to a substrate () respectively; forming a recess part () thereon; performing an alloying process for performing an annealing in order to obtain an ohmic contact; forming a passivation layer () at a period of performing the annealing in the alloying process in order to protect the electron supplying layer () on to a surface of the recess part (), on to the electron supplying layer (), on to a source electrode () and on to a drain electrode (), respectively; removing the passivation layer (); forming a gate insulating film on to a surface at the inner side of the recess part (), on to the electron supplying layer (), on to the source electrode () and on to the drain electrode (), respectively; and forming a gate electrode on to the gate insulating film at a part of the recess part ().

Method of manufacturing GaN-based transistors

The field effect transistor includes a laminated structure in which a buffer layer, and an electron transporting layer (undoped GaN layer), and an electron supplying layer (undoped AlGaN layer) are laminated in sequence on a sapphire substrate. An npn laminated structure is formed on a source region of the electron supplying layer, and a source electrode is formed on the npn laminated structure. A drain electrode is formed in a drain region of the electron supplying layer, and an insulating film is formed in an opening region formed in the gate region. When a forward voltage greater than a threshold is applied to the gate electrode, an inversion layer is formed and the drain current flows. By changing a thickness and an impurity concentration of the p-type GaN layer, the threshold voltage can be controlled. The electrical field concentration between the gate electrode and the drain electrode is relaxed due to the drift layer, and voltage resistance improves.

GaN based semiconductor element

A semiconductor laser device is formed by laminating optical confinement layers and active layers so as to dispose each of said active layers between said optical confinement layers, wherein one of the opposite ends perpendicular to the junction planes of the individual layers in the semiconductor multi-layer film is coated with a low reflection film and the other of the ends is coated with a high reflection film, wherein the low reflection film is an Al O film having a resistivity of 1&times;10 &OHgr;&middot;m or more, preferably 1&times;10 &OHgr;&middot;m or more, and having a stoichiometric ratio composition, which is deposited by, for example, an electron cyclotron resonance sputtering process. The present invention has realized a semiconductor laser device exhibiting a prolonged duration of operating life and having high driving reliability, which is advantageous in that a catastrophic optical damage hardly occurs and a lowering of the optical output after driving at a constant current is suppressed, and thus, it is preferably used as an optical transmitter for the optical communication.

Semiconductor laser device

Growing community of inventors

Tokyo, Japan

Shusuke Kaya